1.

The clitoris is not a button — it's more like a wishbone.

When most people think of the clitoris, they think of the small visible part. But research indicates that it actually has branches that extend down underneath the skin, along either side of the vulva, kind of in a wishbone shape. "These branches can potentially be stimulated from the outside," Debby Herbenick, Ph.D., associate professor at Indiana University and author of The Coregasm Workout (Seal Press, 2015), told BuzzFeed Life. GOOD TO KNOW.

2.

What you think is your vagina is probably actually your vulva.

The vulva refers to the outside, visible parts of your genitalia. It encompasses basically everything you can see — the labia, the clitoris, the urethra, the vaginal opening, and so on — and it's usually what most people mean when they say "vagina."

The vagina, on the other hand, is the muscular passageway that connects the vulva to the cervix.

3.

Vaginas (and vulvas) come in lots of different shapes, sizes, and colors.

There's a good deal of variation from person to person, and there's no such thing as a "standard" vulva — and that's according to science.

4.

When aroused, the vagina can expand to around twice its normal size.

Unaroused, the average vagina is about three to four inches deep. But during sex it can expand to about twice as big, Dr. Herbenick told BuzzFeed Life. That's partially because of a process called vaginal tenting, which is what happens when you get aroused. "When women become aroused, there's more muscular tension in the body," Dr. Herbenick says. "That muscular tension draws the uterus upward, creating more space in the vagina lengthwise."

5.

Not all women are born with hymens.

And for those who do have hymens, they range in thickness and amount of coverage. What this means: You can't actually tell if someone is a virgin or not by doing a "hymen check," according to Dr. Herbenick's book Read My Lips: A Complete Guide to the Vagina and Vulva (Rowman & Littlefield Publishers, 2011).

6.

Your vagina won't be noticeably different after you have babies.

There is actually no statistical difference in average recorded vaginal size between women who've had babies and women who haven't, according to fairly groundbreaking research published in 1996.

If you're interested in buying posters, prints, or postcards from this project, you can email MakeSexNormal@gmail.com — "The proceeds go back to the Center for Sexual Health Promotion [at Indiana University] to support research, education, and hopefully more creative projects," Dr. Herbenick told BuzzFeed Life.

7.

The G-spot maybe doesn't actually exist.

At least not in the sense that there is a button in your vagina that, when pressed, = orgasm. It's a bit more complex than that (surprise!).

First, some G-spot background: For years, researchers have known that there's an area about an inch or two up on the inside front wall of the vagina (the side closest to your belly button) that is associated with intense pleasure. That's why men's magazines love to recommend that your partner should insert a finger into your vagina and make a "come hither" motion to stimulate it.

Here's where it gets a bit complicated: Imaging research and surveys done on twins have failed to find an actual organ, or distinct part of the anatomy, responsible for all that pleasure. Plus, not all women report having G-spots, or being able to find one on themselves.

What does this mean? Well, that new research is pointing to the idea that instead of there being a particular spot or button that causes orgasms, the clitoris, urethra, and front side of the vaginal wall all work together as a "clitourethrovaginal complex." When all three are stimulated just right, it can result in what some people refer to as a vaginal orgasm (aka a G-spot orgasm). Tell your partner not to retire that "come hither" motion just yet.

8.

Feeling like you have to pee during sex, even though you just went? That's normal.

About that clitourethrovaginal complex... well, it can mean that sometimes your partner might be stimulating your urethra (or even bladder) during sex, which can potentially make you feel like you've gotta pee.

There's also a thing called nerve cross-talk, which is where so much is going on down there that your nerves can become confused about what exactly it is they're experiencing, Dr. Herbenick told BuzzFeed Life. "It might feel like you have to pee, but you're actually just becoming aroused," she says.

9.

About half of all American women use vibrators.

In a nationally representative study of 3,800 women between the ages of 18 and 60 in the United States, researchers found that nearly half of the women had used a vibrator for masturbation, and 20% had done so within the past month. More than a third said they'd used one during intercourse, and 41% had used one during foreplay or sex play with a partner.

Also interesting: 84% said they had used a vibrator externally, compared to 64% that had used one internally.

11.

12.

Roughly 16% of women say they've never had an orgasm during intercourse.

And from the same study, about 20 to 30% of women say they only reached orgasm during sex about one in four times...or fewer.

13.

About 30% of women felt some pain during their most recent sexual experience.

There are some women who experience chronic pain from sex, like those who suffer from a condition called vulvodynia. But it is also incredibly common for women to occasionally and unpredictably feel pain while having sex — like if your partner rams your cervix, or if the fit is too tight, or you aren't quite lubricated enough, Dr. Herbenick says. The good news is that most of these reasons are preventable: For example, you can ask your partner to switch to a more comfortable position; you can use lube; or you can ask for foreplay to last longer, so that you can become fully aroused and your vagina can be fully prepared for penetration.

16.

To increase your odds of having an orgasm, mix it up in bed.

Research from the NSSHB shows that women who combine a variety of sex "acts" in one session (as in penetration + hands + oral) are more likely to report having orgasms than people who just stick to one sex act.

18.

There is not really a "normal" amount of discharge to have.

Vaginal discharge amounts vary from person to person, and what's normal for you might not be normal for your friend, Dr. Dweck says. Also, your discharge amount can change depending on what time of the month it is, if you have an infection, and if you're on birth control. It also changes in consistency, color, and smell, depending on all of these things.

19.

You really shouldn't douche.

Your vagina is actually self-cleaning. Think of teardrops, which help clean your eyes — vaginal discharge works in the same way, Dr. Herbenick told BuzzFeed Life.

Douching, on the other hand, can strip your vagina of its natural flora, leaving you more prone to infection. Douching is associated with pelvic inflammatory disorder, bacterial vaginosis, and other health problems, according to a review of studies published in the journal Epidemiologic Reviews.

20.

Your vagina will actually let you know when you're most fertile.

The cervical mucus will become clear and stretchy during ovulation, Dr. Dweck says. You'll probably also notice more of it than usual.

21.

Your vagina will also let you know if there's something wrong.

Things to look out for, according to Dr. Dweck: Itching and irritation. Bloody discharge that isn't related to your period. Discharge that smells foul, or that is noticeably different from what you normally experience. Changes in smell, consistency, amount... If you're experiencing any of these symptoms, you should definitely go see a health care provider.

22.

Herpes and HPV can be spread from skin-to-skin contact, so it's still possible to contract either of these viruses even if you're incredibly diligent about condom usage.

23.

Most women will be exposed to HPV in their lifetime, but may not know about it for years (or ever).

Certain strains of HPV can cause cervical cancer or genital warts, and if you have an irregular pap smear or test positive for HPV, your doctor should work with you to create an individualized plan of care.

But if that does happen, you shouldn't assume the worst: HPV is incredibly common, and most people who are exposed to it never develop any symptoms or health complications because of it. In fact, about 9 out of 10 cases of HPV typically go away on their own within two years, according to the CDC.

Another thing worth noting: It's possible to be exposed to HPV in your twenties and then have it lie dormant, popping up on a routine exam decades down the line.

24.

Other than abstinence, implants and IUDs are the most effective forms of reversible birth control.

Both implants and IUDs are long-term and reversible forms of contraception, and both are over 99% effective at preventing pregnancy. That's why the American Academy of Pediatrics recently recommended both options as the best choices for teenagers as a way to prevent pregnancy.

The implant is a matchstick-sized rod that a doctor has to insert into your arm. It releases the hormone progestin, which prevents ovulation and thickens your cervical mucus, making it less hospitable to sperm. It can last up to three years. Read more about the implant here.

The IUD is a T-shaped device that a doctor inserts directly into your uterus. There are hormonal IUDs, and there is a nonhormonal copper version. IUDs can last for 3 to 12 years, depending on the type. Read all about them here.

Worth noting: The implant and IUD do not protect against any STDs.

25.

You shouldn't have penetrative sex for about six weeks after you give birth.

That's true whether you've had a vaginal birth or a C-section, Dr. Dweck says, and there are a few reasons for it — most related to needing time to heal and avoiding infection. "They can engage in other activities, though, if they feel up to it," she adds.

26.

So many things can give you yeast infections.

Sitting in a wet bathing suit or sweaty workout underwear. Drinking a lot of alcohol, or eating a ton of sugar. And being on antibiotics, because they can kill off all the good bacteria in your vagina and cause an imbalance that is hospitable to the fungus. Ick.

Good news: Eating yogurt with live cultures in it may help restore that balance, Dr. Dweck says. And there is a pill your doc can prescribe (called Diflucan), as well as OTC treatments you can get at any drug store that will help you get rid of it.

27.

The vagina is tilted at roughly a 130-degree angle, which is why you have to insert tampons by aiming them at your back.

THAT said, things change with time. "The vaginal angle flattens a bit, which may make vaginal intercourse feel different to women as they age and go through menopause," Dr. Herbenick writes in Read My Lips: A Complete Guide to the Vagina and Vulva (Rowman & Littlefield Publishers, 2011).

28.

People get things stuck in their vaginas sometimes. Actually, often.

Most common are condoms and tampons, which can be tough to retrieve on your own. If this happens to you, and you can't get... whatever it is... out by yourself, you can absolutely go to the doctor to get it out for you.

"I can't even tell you some of the things I've fished out," Dr. Dweck says. "But what's most important is that in the gynecology world, we don't pass judgment." It's better to swallow your pride and get help than let it sit there. When it comes to tampons, leaving it in can result in a terrible smell; for harder objects (like vibrators, whipped cream container tops, and so on), leaving it in could leave you susceptible to cutting and injuring yourself. Yikes.

29.

…but you can't actually lose something in there. Whew!

The cervical wall will block anything sizeable from migrating into your body. "It's not going anywhere," Dr. Dweck says. "It'll remain at the top of your vagina at the cervix, and it'll be retrieved."

The study about pubic hair removal trends showed a correlation between age and pubic hair removal. An earlier version of this post misstated that getting older is the cause of those changing hair removal trends. Thanks to several commenters for pointing out the mistake. Also, implants are the most effective form of reversible birth control. An earlier version of this post said that IUDs were the most effective form of reversible birth control. (H/T: @cbpolis)